Study On High Performance Adsorbent And Its Adsorption Characteristics Based On VOCs Treatment

Petrochemical enterprise is one of the important industrial emission sources of VOCs,according to the characteristics of the craft waste gas,combustion flue gas and torch incineration system gas and other organized waste gas,which is the higher gas flow rates and the lower VOCs emission concentration,this paper was conducted to investigate the adsorption behavior of VOCs on activated carbon by using activated carbon adsorption technology and establishing adsorption experimental apparatus:to explore the relationship between activated carbon surface properties,pore structure,physical parameter of VOCs,adsorption properties of activated carbon,to explain the mechanism of adsorption process.Then the activated carbon was prepared from petroleum coke by KOH high temperature activation method,and the effects of process conditions on the pore structure of activated carbon,activation yield and adsorption properties of toluene were analyzed.Through the dynamic adsorption experiment of activated carbon on 5 specific adsorbates determination,3 kinds of activated carbon are selected,and the structure is characterized,these investigations show that the pore structure of activated carbon AC-3based coal is more developed than the activated carbon AC-1 and coconut shell activated carbon AC-2,the adsorption capacity of AC-3 on the 5 kinds of specific adsorbates is the largest;These activated carbons have no functional group on the surface,so the contribution of surface chemical properties to adsorption capacity is little;activated carbon adsorption capacity of toluene,benzene and acetone is positively linearly correlated with the adsorbates’molecular weight,molecular diameter,density and the boiling point,is negatively linear correlated with saturated vapor pressure and polarity,the physical parameters and the adsorption capacity of cyclohexane,dichloromethane do not comply with this law;the adsorption experimental data on 5kinds of adsorbent were fitted to Bangham adsorption model which is one of the four models have the highest fitting degree,followed by quasi-one-order and quasi-two-order and Elovich model,so the adsorption of VOCs on activated carbon is mainly controlled by pore diffusion.The adsorption process dynamic penetration curve were determined,the influence of the shape of breakthrough curve,breakthrough time and other aspects of VOCs concentration,flow rate and operating temperature and other factors on the dynamic adsorption behavior of activated carbon were investigated,the research shows that the temperature is not conducive to the adsorption process;the greater gas flow rate and gas concentration,the more easily penetrate and saturation;if the bed is filled with smaller density,it’s more easily penetrated,but the saturation point is postponed than high density;activated carbon adsorption of acetone is more affected by air humidity than toluene and dichloromethane,this may be related to the solubility and polarity of the adsorbate,and the competitive ability of toluene is stronger than that of benzene in two component adsorption experiment.The study on preparation experimental of activated carbon by KOH activation from petroleum coke show that:the rate of KOH/Coke（K/C）is greater,the activation effect is more better,when the value of K/C is 5:1,the maximum adsorption capacity of toluene was 353.84 mg·g^-1;Activation temperature have a greater impact on the pore structure forming of activated carbon,increasing the temperature,the number of micropores increases;when the activation time is less than 2.5 h,activation effect is better while increased activation time,but after more than 2.5 h,the formed micropores will be etched which affects the activation effect and the adsorption performance of activated carbon;When the pre activation time is not more than 30 min,the activation effect is more obvious with the increase of the pre activation time.However,continuing to increase the pre-activation time,the increased rate of activation will obviously reduce;The specific surface area of activated carbon can reach up to1932.45 m²·g^-1,and the potential of microporous plastic is very large.